The IUCN Red List, CITES appendices, and the United States Endangered Species Act list the status of Aplodinotus grunniens as being a species of “least concern” or having “no special status.” This indicates that populations are not threatened in the near future.
US Federal List: no special status
CITES: no special status
Humans contribute to a great amount of predation on freshwater drum. Commercially up to 453,592 kg (1 million pounds) is harvested per year. Immature drum are preyed on by many different predatory fishes such as Sander vitreus, Esox masquinongy, Esox lucius, Aplodinotus grunniens, and gulls (Larus), such as Larus argentatus.
Known Predators:
Freshwater drum have a distinctive appearance. They are a silver, deep-bodied fish that are compressed laterally. An unusual characteristic of these fish is that their lateral line extends into their rounded caudal fin. They also have a long dorsal fin relative to their total length that contains a deep notch. According to Smith (2001) the mouth is sub terminal with a blunt rounded snout. The scales are ctenoid and the lateral line scales can range from 49 to 53. The anal fin has two spines, the first being much shorter than the second, and seven soft rays. Freshwater drum can reach lengths up to .91 m (three feet) and weights up to 24 kg (55 pounds). On average they range in size from 31 cm to 71 cm ( 12 to 28 inches) and weights from .45 kg to 3.6 kg (1 to 8 pounds).
Range mass: 24 (high) kg.
Average mass: 0.45-3.6 kg.
Range length: 910 (high) mm.
Average length: 310-710 mm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: sexes alike
Not much information is available on the lifespan of freshwater drum in captivity. It is known that they can reach the age of 13 in the wild and average between 6 to 8 years natural longevity.
Range lifespan
Status: wild: 13 (high) years.
Typical lifespan
Status: wild: 6 to 8 years.
Freshwater drum inhabit backwaters and areas of slack current in a wide range of habitats including deep pools in medium to large rivers and large, deep to shallow lacustrine environments. They are a benthic fish that particularly like silty to rocky substrates.
Habitat Regions: temperate ; tropical ; freshwater
Aquatic Biomes: benthic ; lakes and ponds; rivers and streams
Freshwater drum are the only members of the family Sciaenidae that inhabit freshwater. They have a vast distribution range that extends from as far north as the Hudson Bay to their extreme southern range in the Rio Usumacinata Basin of Guatemala. They are found as far east as the western banks of the Appalachian Mountain range in the eastern U.S. and extending as far west as Texas, Oklahoma and Kansas. They are considered to be one of the most wide-ranging fish species in North America.
Biogeographic Regions: nearctic (Native )
Freshwater drum feed on prey at all hours of the night. They peruse the bottom in schools in search of many different items. They generally root around and move rocks and other substrates to flush their prey. Adults feed primarily on aquatic insects such as mayflies, small fish (in particular shad (Alosa) and immature drum) and mollusks. During the early larval stage freshwater drum feed primarily on the larval stages of other fishes. After reaching 12 mm they begin to feed on zooplankton (Clark and Pearson, 1979; as cited in Etnier and Starnes, 1993). Juveniles feed on larval stages of mayflies and caddisflies. Freshwater drum are equipped with heavy pharyngeal teeth that aid in the consumption of snails and the introduced Dreissena polymorpha.
Animal Foods: fish; eggs; carrion ; insects; mollusks; terrestrial worms; aquatic crustaceans; zooplankton
Primary Diet: carnivore (Piscivore , Insectivore ); omnivore
Freshwater drum are known for their feeding on the notorious zebra mussels Dreissena polymorpha. They do not control populations however they may contribute to high numbers of mortality in these nuisance mussells. It is documented that many types of mussels use freshwater drum as a host in their reproductive cycle.
Commensal/Parasitic Species:
Freshwater drum are growing in popularity and in some cases they are recognized as a sport fish. They are known for their great fighting ability and their large size. They are popular meat in some areas. In some cases drum make a great bait to catch other fish species. These fish also have exceptionally large inner ear bones called otoliths. They are called “lucky stones” and are collected for good luck. Many otoliths have been found around old Indian settlements and were traded far outside of their natural range. Archeologists believe that they were collected by indigenous peoples and worn as jewelry.
Positive Impacts: food ; body parts are source of valuable material; controls pest population
There are no known adverse effects of freshwater drum on humans.
Freshwater drum begin life when the female's egg becomes fertilized by the male. The fertilized egg then hatches after 48 to 96 hours. The larvae are 3 mm at hatching and stay at the surface for three days, or until they are capable of swimming on their own. They then proceed to move into deeper waters to begin feeding and are considered juveniles at 15 mm. They can reach lengths up to 85 mm during their first year, and reach sizes up to 150 mm the next. The size of freshwater drum varies based on food and habitat availability. The sexes are not dimorphic.
Freshwater drum communicate by making drumming, or croaking sounds with specialized muscles that vibrate against their air bladders. This feature gives the species its name, grunniens, latin for "grunting". These muscles only develop in males. Drumming is thought to excite males and females to assemble in a breeding area.
Communication Channels: acoustic
Other Communication Modes: vibrations
Perception Channels: tactile ; acoustic ; chemical
Freshwater drum breed seasonally in open water. The eggs are fertilized and left floating near the surface of the water, where the eggs, and subsequently the larvae, are carried by currents. This unique characteristic is thought to be the explanation of their wide distribution. Freshwater drum are seemingly promiscuous because males and females disperse eggs and sperm into the water column where fertilization is rather random. However scientific evidence to justify this statement has not been documented.
Mating System: polygynandrous (promiscuous)
Males generally reach maturity at the age of four while females usually reach maturity around age five and into their sixth year of life. Spawning takes place when water temperatures reach 20° C, usually between the months of May and June. The fish spawn within the water column. According to Etnier and Starnes (1993) one female can produce 40,000 to 60,000 ova, although most of these eggs are preyed on almost immediately. Fertilized eggs float near the surface of the water for two to four days before hatching. Larvae stay attached to the surface film until they obtain enough muscle strength to swim into deeper water. This usually requires at least three more days. Growth is rapid in young fish and tends to slow down with age.
Breeding interval: Freshwater drum breed once a year for 6 to 7 weeks in late spring to early summer.
Breeding season: Spawning takes place between May and June and when water temperatures reach 20° C.
Range number of offspring: 40,000 to 60,000.
Range gestation period: 1 to 4 days.
Range time to independence: 5 to 8 days.
Average time to independence: 6 days.
Range age at sexual or reproductive maturity (female): 5 to 6 years.
Range age at sexual or reproductive maturity (male): 4 to 6 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (External ); broadcast (group) spawning; oviparous
Average number of offspring: 50000.
There is no parental involvement among freshwater drum after spawning.
Parental Investment: no parental involvement; pre-fertilization (Provisioning)
The freshwater drum, Aplodinotus grunniens, is a fish endemic to North and Central America. It is the only species in the genus Aplodinotus, and is a member of the family Sciaenidae. It is the only North American member of the group that inhabits freshwater for its entire life.[3] Its generic name, Aplodinotus, comes from Greek meaning "single back", and the specific epithet, grunniens, comes from a Latin word meaning "grunting".[4] It is given to it because of the grunting noise that mature males make. This noise comes from a special set of muscles within the body cavity that vibrate against the swim bladder. The purpose of the grunting is unknown, but due to it being present in only mature males and during the spawning season, it is assumed to be linked to spawning.[3][5]
The drum typically weighs 5–15 lb (2.3–6.8 kg). The world record was caught on Nickajack Lake in Tennessee, and weighed in at 54 lb 8 oz (24.7 kg). The freshwater drum is gray or silvery in turbid waters and more bronze or brown colored in clearer waters. It is a deep bodied fish with a divided dorsal fin consisting of 10 spines and 29–32 rays.
The freshwater drum is also called Russell fish, shepherd's pie, gray bass,[6] Gasper goo, Gaspergou,[7] gou,[7] grunt, grunter,[6] grinder, gooble gobble, and croaker. It is commonly known as sheephead and sunfish in parts of Canada,[8] the United Kingdom,[9] and the United States.[6][7][10][11]
Freshwater drum are the only North American member of their family to exclusively inhabit freshwater (freshwater family members in genera Pachypops, Pachyurus, Petilipinnis and Plagioscion are from South America,[12] while Boesemania is Asian[13]). Their great distribution range goes as far north as the Hudson Bay, and reaches as far south as Guatemala. Their longitudinal distribution goes as far east as the eastern Appalachians and stretches as far west into Texas, Kansas, and Oklahoma.[14] Freshwater drum are considered to be one of the most wide-ranging species in North America.
The freshwater drum prefers clear water, but it is tolerant of turbid and murky water. They prefer the bottom to be clean sand and gravel substrates.[15]
The diet of the freshwater drum is generally benthic and composed of macroinvertebrates (mainly aquatic insect larvae and bivalve mussels), as well as small fish in certain ecosystems.[16] Freshwater drum show distinct seasonal differences in their diet. In April and May, the drum feeds on dipterans. During these months, dipterans make up about 50 percent of the freshwater drum's diet.[17] In August through November, they tend to eat fish (which are primarily young-of-the-year gizzard shad). The percentage of fish in their diet at this time ranges from 52 to 94 percent.[17] Other items in the drum's diet are mollusks and crayfish.
The freshwater drum competes with several organisms. During its early stages in Lake Erie, it has been shown to compete with yellow perch, the trout-perch, and the emerald shiner.[18] During its adult lifetime, it competes with yellow perch and silver chub in deep water, and competes with black bass in the shoal areas.[18]
Predators on drum include humans and other fish. During its first year, the freshwater drum serves as a forage fish for many species of predatory fish. These include smallmouth bass, walleye, and many other piscivores.[18] After its first year, the primary predators on freshwater drum are humans. The drum is an important commercial crop on the Mississippi River, but in other areas it constitutes only a small portion of the commercial catch.[3] Consistent with other sciaenids, freshwater drum are strongly nocturnal with the bulk of most catches being derived from night angling/sampling.[19] Commercial fisheries are present for this species, although market price tends to be quite low. Thus, many freshwater drum are harvested as bycatch from targeted higher-value species.[20]
There has been some research on the freshwater drum's impact on the invasive zebra mussel in northern lakes and rivers. Zebra mussels are consumed by freshwater drum once they reach a length of 25 cm (9.8 in), but drum under 35 cm (14 in) in length only eat small mussels and reject the larger ones.[21] The fish larger than 35 cm (14 in) exhibit less selectivity and consume mussels relative to their availability in lakes. These larger fish are not restricted by their ability to crush zebra mussels, but they are restricted by the size of the clumps that they can remove.[21] The drums' eating of zebra mussels contributes to a high mussel mortality, but not enough to have an impact on their spread, or control the population.[15]
During the summer, freshwater drums move into warm, shallow water that is less than 33 ft (10 m) deep.[22] The freshwater drum then spawn during a six to seven-week period from June through July when the water reaches a temperature of about 65 °F (18 °C).[23] During the spawn, females release their eggs into the water column and males release their sperm. Fertilization is random.[15] Males generally reach sexual maturity at four years, whereas females reach maturity at five or six years.[15] Females from six to nine years old have a clutch size of 34,000 to 66,500 eggs and they spawn in open water giving no parental care to their larvae.[23] The eggs then float to the top of the water column and hatch between two and four days.[15] Due to the broadcasting of eggs in open water and lack of parental care, many eggs and larvae fall victim to predation upon hatching, the pro-larvae average 3.2 mm (0.13 in) long. The post-larval stage begins about 45 hours after hatching and a length of 4.4 mm (0.17 in) is attained.[23]
Females grow at a faster rate than the males and adult characteristics start to form at a length of 15 mm (0.59 in).[22][23] Females continue to outgrow the male throughout their lives reaching a length of 12 to 30 in (30 to 76 cm). Usually the freshwater drum weighs 2–10 lb (0.91–4.54 kg), but they can reach well over 36 lb (16 kg).[15] Freshwater drums are long-lived and have attained maximum ages of 72 years old in Red Lakes, Minnesota and 32 years old in the Cahaba River, Alabama.[24] Though they can reach very old age, the average age of a freshwater drum is between 6 and 13 years.[15] In some cases, otoliths provide such a long record of growth that they can be studied using the same techniques as those used by dendochronologists. [25]
There are few management practices for the species, and in many regions daily bag limits are unlimited. The freshwater drum is not federally or state listed by any states. Although the commercial harvest is up to 1 million pounds per year, they are in no danger of overharvest.[15] In the Mississippi River alone, the commercial catch has reached about 300,000 lb (140,000 kg) in recent years.[26] Due to its abundance, many states allow bowfishing and other non-conventional means to harvest the fish.
{{cite journal}}: CS1 maint: uses authors parameter (link) The freshwater drum, Aplodinotus grunniens, is a fish endemic to North and Central America. It is the only species in the genus Aplodinotus, and is a member of the family Sciaenidae. It is the only North American member of the group that inhabits freshwater for its entire life. Its generic name, Aplodinotus, comes from Greek meaning "single back", and the specific epithet, grunniens, comes from a Latin word meaning "grunting". It is given to it because of the grunting noise that mature males make. This noise comes from a special set of muscles within the body cavity that vibrate against the swim bladder. The purpose of the grunting is unknown, but due to it being present in only mature males and during the spawning season, it is assumed to be linked to spawning.
The drum typically weighs 5–15 lb (2.3–6.8 kg). The world record was caught on Nickajack Lake in Tennessee, and weighed in at 54 lb 8 oz (24.7 kg). The freshwater drum is gray or silvery in turbid waters and more bronze or brown colored in clearer waters. It is a deep bodied fish with a divided dorsal fin consisting of 10 spines and 29–32 rays.
The freshwater drum is also called Russell fish, shepherd's pie, gray bass, Gasper goo, Gaspergou, gou, grunt, grunter, grinder, gooble gobble, and croaker. It is commonly known as sheephead and sunfish in parts of Canada, the United Kingdom, and the United States.
